You know, I don't even believe that anymore. It is quite possible that even a million casualties on American soil would not sufficiently harden the national will.
In my younger days I used to wonder why Rome fell. How they could have let it happen. Superior force, superior civilization...But force is meaningless without resolve, and civilization is a delicate thing.
And then there's the matter of birth rates and oil wealth. In fact, the only glimmer of hope I have is that something will be found to replace oil, or manufacture it by some wonderful new means. That would take the wind right out of the Islamic sails.
I'm reminded of a passage in a book by novelist Howard Fast..."The Jews, Story of A People."
He wrote, "The iron sword and the horse and chariot were the great equalizers; they catapulted the herdsman into history. Desert-parched, bitter with longing, the foot-bound wanderer of the desert and the badlands was suddenly mobile...On foot they had been helpless; but suddenly they stood in chariots, drove prancing horses, cast iron-shod spears. Now they began to hack and bite at the land which their mythology had assured them was theirs by right of first usage..."
This time, what spurs the barbarian is not a technology, but a fuel. Take away the oil---or its value---and you would take away their motive power. Otherwise they will hack and bite at the land of Israel, and the edges of civilization everywhere.
The fuel is what enables the barbarian ... his motivation comes from an aggressive and psychotic ideology.
However, just as in Nazi Germany, the number of true psychotics is actually pretty small, and the main mass of the populace pretty much gets pulled along in their wake.
The key to dealing with the barbarian is to deal with the main mass of the populace.